Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rat...Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.展开更多
A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for r...A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors（SPD） and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power.展开更多
A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation （GPCM）, which is suitable for the area where the work conditi...A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation （GPCM）, which is suitable for the area where the work condition is poor and a large flow rate is required. It is difficult to control the GPCM system because the system is discrete. With consideration of the stability and speediness of the GPCM position servo control system, a control strategy is developed through the theoretical and ex-perimental analyses. The control strategy integrates the merits of Bang-Bang control, PID control and fuzzy control. With this hybrid control strategy, the electro hydraulic control system has good per-formances, and the servo control is carried out with GPCM through on-off valves.展开更多
Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error p...Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error propagation.Mismatch of parameters and synchronization error between the receiver and transmitter will arouse high bit error rate.To solve these problems,a demodulation algorithm of CPPM based on particle filtering is proposed.According to the mathematical model of the system,it tracks the real signal by online separation in demodulation.Simulation results show that the proposed method can track the true signal better than the traditional CPPM scheme.What's more,it has good synchronization robustness,reduced error propagation by wrong decision and low bit error rate.展开更多
γ-Aminobutyric acid(GABA) neurotransmission alterations have been implicated to play a role in depression pathogenesis. While GABA_(A) receptor positive allosteric modulators are emerging as promising in clinical pra...γ-Aminobutyric acid(GABA) neurotransmission alterations have been implicated to play a role in depression pathogenesis. While GABA_(A) receptor positive allosteric modulators are emerging as promising in clinical practice, their precise antidepressant mechanism remains to be further elucidated. The aim of the present study was to investigate the effects of LY-02, a novel compound derived from the metabolite of timosaponin, on depression in animals and its mechanism. The results of behavioral tests showed that LY-02 exhibited better antidepressant effects in both male C57BL/6 mice and Sprague Dawley(SD) rats. The results of cellular voltage clamp experiments showed that LY-02 enhanced GABA-mediated currents in HEK293T cells expressing recombinant α6β3δ subunitcontaining GABA_(A) receptors. Electrophysiological recording from brain slices showed that LY-02 decreased the amplitude of spontaneous inhibitory postsynaptic current(sIPSC) and increased action potentials of pyramidal neurons in the medial prefrontal cortex(mPFC) of C57BL/6 mice. Western blot results showed that LY-02 dose-dependently up-regulated the protein expression levels of brain-derived neurotrophic factor(BDNF), tropomyosin related kinase B(TrkB) and postsynaptic density protein 95(PSD-95) in m PFC of mice. The above results suggest that LY-02, as a positive modulator of GABA_(A) receptors, reduces inhibitory neurotransmission in pyramidal neurons. It further activates the BDNF/TrkB signaling pathway, thus exerting antidepressant effects. It suggests that LY-02 is a potential novel therapeutic agent for depression treatment.展开更多
Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effectiv...Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effective treatment and avoid over-high temperature. Proposed in this paper is a method to modulate the temperature distribution in the focal region. It superimposes two signals which focus on two preset different targets with a certain distance. Then the temperature distribution is modulated by changing triggering time delay and amplitudes of the two signals. The simulation model is established based on an 82-element transducer and computed tomography （CT） data of a volunteer＇s head. A finite- difference time-domain （FDTD） method is used to calculate the temperature distributions. The results show that when the distances between the two targets respectively are 7.5-12.5 mm on the acoustic axis and 2.0-3.0 mm in the direction perpendicular to the acoustic axis, a focal region with a uniform temperature distribution （64-65 ℃） can be created. Moreover, the volume of the focal region formed by one irradiation can be adjusted （26.8-266.7 mm3） along with the uniform temperature distribution. This method may ensure the safety and efficacy of HIFU brain tumor therapy.展开更多
Objective： To evaluate if the combination of both prone position on a belly board and intensity-modulated radiotherapy （IMRT） further reduces the radiation dose to small bowel in pelvic RT for gynecologic malignanc...Objective： To evaluate if the combination of both prone position on a belly board and intensity-modulated radiotherapy （IMRT） further reduces the radiation dose to small bowel in pelvic RT for gynecologic malignancies. Methods： Conformal pelvic RT plans were computed in 13 patients with gynecologic malignancies who had pre-existing planning computed tomography （CT） scans in both the supine position and prone position on a belly board. There were 10 cervical cancer and 3 endometrial cancer patients. A limited arc technique （180° arc length） and an extended arc technique （340° arc length） were used in IMRT plans. Normal tissue regions of interest （ROI） included small bowel, large bowel and bladder. Dose and volume for normal tissue structures were traced and compared between supine and prone plans using the paired t-test. Results： For the limited arc technique, prone position using a belly board device improved small bowel sparing. Analysis of the results showed a 12~26 Gy reduction of volume of small bowel irradiation compared to the supine position. With the extended arc technique, there was no obvious radiation reduction in the prone position. Large bowel and bladder dose showed no significant differences between prone and supine position with either technique. Conclusion： Prone positioning on a belly board decreases the small bowel dose in gynecologic pelvic IMRT, and the magnitude of improvement depended on the limited arc IMRT technique used.展开更多
A series of new 6-substituted 3 H-quinazolin-4-ones（3 a-3 d） were designed, synthesized and evaluated as the type I positive allosteric modulators（PAMs） of human α7 n ACh R expressed in Xenopus ooctyes by two-ele...A series of new 6-substituted 3 H-quinazolin-4-ones（3 a-3 d） were designed, synthesized and evaluated as the type I positive allosteric modulators（PAMs） of human α7 n ACh R expressed in Xenopus ooctyes by two-electrode voltage clamp. However, no compound showed a better efficacious PAM than lead compound 2 in the presence of acetylcholine（100 μM）. The structure-activity relationship（SAR） analysis suggested that thiazolo[4,5-d]pyrimidin-7（6 H）-one was the key biological skeleton.展开更多
Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for...Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for Impulse Radio Ultra-WideBand (IR-UWB) communication systems. This modulation scheme uses pulses with equal amplitude and different widths to carry different information. The receiver employs differences between similarity coefficients among these pulses to distinguish different information. Both theoretical analysis and simulation results verify that this novel scheme has a Signal to Noise Ratio (SNR) gain of about 1.75 dB compared with or- thogonal binary PPM, and has an SNR loss of about 1.4 dB compared with binary PAM. Although both the theoretical analysis and simulations are based on time-hopping multiple access, this modulation scheme can also be applied to other accessing techniques of UWB communication systems.展开更多
A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expre...A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expressed in Xenopus ooctyes.Compound 4g as a positive allosteric modulator(PAM)showed better efficacy than lead compound 3(HZZ-A-11)with an EC50 value of 1.23±0.41μM.Further pharmacological evaluation of compound 4g might lead to the developmental potential for therapy of cognitive deficits commonly shared by neuropsychiatric disorders,such as schizophrenia and Alzheimer’s disease.展开更多
针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降...针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降低对硬件算力的要求;同时,利用PPM调制中脉冲间隔形成的特点和脉冲信号的快速衰减特性抑制高频水声信道多径干扰,避免采用高复杂度的信道均衡处理。实验室水池实验表明了采用该方案的通信样机在米级距离达到Mbps级传输速率的有效性。展开更多
为满足多数工业场景下钢板表面缺陷检测的需求,针对钢板表面缺陷检测准确率低及小目标缺陷检测率低等问题,文中提出了一种基于改进YOLOv5(You Only Look Once version 5)的钢板表面缺陷检测算法。在YOLOv5的基础上将CBAM(Convolution Bl...为满足多数工业场景下钢板表面缺陷检测的需求,针对钢板表面缺陷检测准确率低及小目标缺陷检测率低等问题,文中提出了一种基于改进YOLOv5(You Only Look Once version 5)的钢板表面缺陷检测算法。在YOLOv5的基础上将CBAM(Convolution Block Attention Module)注意力模块嵌入到主干网络中,提高网络检测精度。加入上下文增强模块,提高了算法对小目标的检测性能。使用NWD(Normalized Wasserstein Distance)度量标准代替原YOLOv5中的IoU(Intersection over Union)度量,提高了网络对裂纹缺陷的识别精确度。实验结果表明,钢板表面缺陷检测算法对裂纹、夹杂、斑块、麻点、压入氧化铁皮、划痕6类缺陷的平均检测精度达到了88.9%,每秒帧数达到110.4 frame·s-1,其中小目标裂纹准确率达到75%。展开更多
基金supported by the National Natural Science Foundation of China(No.52175269)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+2 种基金Science and Technology Research Project of Education Department of Jilin Province(JJKH20231146KJ,JJKH20241262KJ)Project ZR2024ME104 supported by Shandong Provincial Natural Science FoundationChina Postdoctoral Science Foundation(No.2024M751086).
文摘Numerous arthropods evolve and optimize sensory systems, enabling them to effectively adapt complex and competitive habitats. Typically, scorpions can precisely perceive the prey location with the lowest metabolic rate among invertebrates. This biological phenomenon contrasts sharply with engineered systems, which generally associates high accuracy with substantial energy consumption. Inspired by the Scorpion Compound Slit Sensilla (SCSS) with a stress field modulation strategy, a bionic positioning sensor with superior precision and minimal power consumption is developed for the first time, which utilizes the particular Minimum Positioning Units (MPUs) to efficiently locate vibration signals. The single MPU of the SCSS can recognize the direction of collinear loads by regulating the stress field distribution and further, the coupling action of three MPUs can realize all-angle vibration monitoring in plane. Experiments demonstrate that the bionic positioning sensor achieves 1.43 degrees of angle-error-free accuracy without additional energy supply. As a proof of concept, two bionic positioning sensors and machine learning algorithm are integrated to provide centimeter (cm)-accuracy target localization, ideally suited for the man-machine interaction. The novel design offers a new mechanism for the design of traditional positioning devices, improving precision and efficiency in both the meta-universe and real-world Internet-connected systems.
基金Project supported by Tsinghua University Initiative Scientific Research Program,China(Grant No.2014z21035)
文摘A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors（SPD） and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power.
文摘A hybrid control strategy has been designed and developed for the electro-hydraulic posi-tion servo control system with generalized Pulse code modulation （GPCM）, which is suitable for the area where the work condition is poor and a large flow rate is required. It is difficult to control the GPCM system because the system is discrete. With consideration of the stability and speediness of the GPCM position servo control system, a control strategy is developed through the theoretical and ex-perimental analyses. The control strategy integrates the merits of Bang-Bang control, PID control and fuzzy control. With this hybrid control strategy, the electro hydraulic control system has good per-formances, and the servo control is carried out with GPCM through on-off valves.
基金Supported by the National Natural Science Foundation of China(No.41074090)Henan Science and Technology Key Project(No.092102210360)+1 种基金Henan Provincial Department of Education Science ang Technology Key Project(No.13A510330)Doctorate Program of Henan Polytechnic University(No.B2009-27)
文摘Traditional chaotic pulse position modulation(CPPM)system has many drawbacks.It introduces delay into the feedback loop,which will lead to divergence of chaotic map easily.The wrong decision of data will cause error propagation.Mismatch of parameters and synchronization error between the receiver and transmitter will arouse high bit error rate.To solve these problems,a demodulation algorithm of CPPM based on particle filtering is proposed.According to the mathematical model of the system,it tracks the real signal by online separation in demodulation.Simulation results show that the proposed method can track the true signal better than the traditional CPPM scheme.What's more,it has good synchronization robustness,reduced error propagation by wrong decision and low bit error rate.
文摘γ-Aminobutyric acid(GABA) neurotransmission alterations have been implicated to play a role in depression pathogenesis. While GABA_(A) receptor positive allosteric modulators are emerging as promising in clinical practice, their precise antidepressant mechanism remains to be further elucidated. The aim of the present study was to investigate the effects of LY-02, a novel compound derived from the metabolite of timosaponin, on depression in animals and its mechanism. The results of behavioral tests showed that LY-02 exhibited better antidepressant effects in both male C57BL/6 mice and Sprague Dawley(SD) rats. The results of cellular voltage clamp experiments showed that LY-02 enhanced GABA-mediated currents in HEK293T cells expressing recombinant α6β3δ subunitcontaining GABA_(A) receptors. Electrophysiological recording from brain slices showed that LY-02 decreased the amplitude of spontaneous inhibitory postsynaptic current(sIPSC) and increased action potentials of pyramidal neurons in the medial prefrontal cortex(mPFC) of C57BL/6 mice. Western blot results showed that LY-02 dose-dependently up-regulated the protein expression levels of brain-derived neurotrophic factor(BDNF), tropomyosin related kinase B(TrkB) and postsynaptic density protein 95(PSD-95) in m PFC of mice. The above results suggest that LY-02, as a positive modulator of GABA_(A) receptors, reduces inhibitory neurotransmission in pyramidal neurons. It further activates the BDNF/TrkB signaling pathway, thus exerting antidepressant effects. It suggests that LY-02 is a potential novel therapeutic agent for depression treatment.
基金Project supported by the National Natural Science Foundation of China(Grant No.81272495)the Natural Science Foundation of Tianjin,China(Grant No.16JC2DJC32200)
文摘Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effective treatment and avoid over-high temperature. Proposed in this paper is a method to modulate the temperature distribution in the focal region. It superimposes two signals which focus on two preset different targets with a certain distance. Then the temperature distribution is modulated by changing triggering time delay and amplitudes of the two signals. The simulation model is established based on an 82-element transducer and computed tomography （CT） data of a volunteer＇s head. A finite- difference time-domain （FDTD） method is used to calculate the temperature distributions. The results show that when the distances between the two targets respectively are 7.5-12.5 mm on the acoustic axis and 2.0-3.0 mm in the direction perpendicular to the acoustic axis, a focal region with a uniform temperature distribution （64-65 ℃） can be created. Moreover, the volume of the focal region formed by one irradiation can be adjusted （26.8-266.7 mm3） along with the uniform temperature distribution. This method may ensure the safety and efficacy of HIFU brain tumor therapy.
文摘Objective： To evaluate if the combination of both prone position on a belly board and intensity-modulated radiotherapy （IMRT） further reduces the radiation dose to small bowel in pelvic RT for gynecologic malignancies. Methods： Conformal pelvic RT plans were computed in 13 patients with gynecologic malignancies who had pre-existing planning computed tomography （CT） scans in both the supine position and prone position on a belly board. There were 10 cervical cancer and 3 endometrial cancer patients. A limited arc technique （180° arc length） and an extended arc technique （340° arc length） were used in IMRT plans. Normal tissue regions of interest （ROI） included small bowel, large bowel and bladder. Dose and volume for normal tissue structures were traced and compared between supine and prone plans using the paired t-test. Results： For the limited arc technique, prone position using a belly board device improved small bowel sparing. Analysis of the results showed a 12~26 Gy reduction of volume of small bowel irradiation compared to the supine position. With the extended arc technique, there was no obvious radiation reduction in the prone position. Large bowel and bladder dose showed no significant differences between prone and supine position with either technique. Conclusion： Prone positioning on a belly board decreases the small bowel dose in gynecologic pelvic IMRT, and the magnitude of improvement depended on the limited arc IMRT technique used.
基金National Natural Science Foundation of China(NSFC,Grant No.21572011)Ministry of Science and Technology of China(Grant No.2013CB531302)
文摘A series of new 6-substituted 3 H-quinazolin-4-ones（3 a-3 d） were designed, synthesized and evaluated as the type I positive allosteric modulators（PAMs） of human α7 n ACh R expressed in Xenopus ooctyes by two-electrode voltage clamp. However, no compound showed a better efficacious PAM than lead compound 2 in the presence of acetylcholine（100 μM）. The structure-activity relationship（SAR） analysis suggested that thiazolo[4,5-d]pyrimidin-7（6 H）-one was the key biological skeleton.
文摘Since the poor performance of orthogonal binary Pulse Position Modulation (PPM) compared with binary Pulse Amplitude Modulation (PAM), this paper presents a new modulation scheme named Pulse Width Modulation (PWM) for Impulse Radio Ultra-WideBand (IR-UWB) communication systems. This modulation scheme uses pulses with equal amplitude and different widths to carry different information. The receiver employs differences between similarity coefficients among these pulses to distinguish different information. Both theoretical analysis and simulation results verify that this novel scheme has a Signal to Noise Ratio (SNR) gain of about 1.75 dB compared with or- thogonal binary PPM, and has an SNR loss of about 1.4 dB compared with binary PAM. Although both the theoretical analysis and simulations are based on time-hopping multiple access, this modulation scheme can also be applied to other accessing techniques of UWB communication systems.
基金National Natural Science Foundation of China aw arded to Q.Sun(NSFC,Grant No.81973169,21572011)and K.W.Wang(NSFC,Grant No.81537410)the Ministry of Science and Technology of China to K.W.Wang(Grant No.2014ZX09507003-006-004)。
文摘A series of 2-arylamino-1,3,5-triazine derivatives(4a–4g),which were designed and synthesized via Sonogashira coupling reaction,were evaluated using two-electrode voltage clamp(TEVC)recordings of humanα7 nAChR expressed in Xenopus ooctyes.Compound 4g as a positive allosteric modulator(PAM)showed better efficacy than lead compound 3(HZZ-A-11)with an EC50 value of 1.23±0.41μM.Further pharmacological evaluation of compound 4g might lead to the developmental potential for therapy of cognitive deficits commonly shared by neuropsychiatric disorders,such as schizophrenia and Alzheimer’s disease.
文摘针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降低对硬件算力的要求;同时,利用PPM调制中脉冲间隔形成的特点和脉冲信号的快速衰减特性抑制高频水声信道多径干扰,避免采用高复杂度的信道均衡处理。实验室水池实验表明了采用该方案的通信样机在米级距离达到Mbps级传输速率的有效性。
文摘为满足多数工业场景下钢板表面缺陷检测的需求,针对钢板表面缺陷检测准确率低及小目标缺陷检测率低等问题,文中提出了一种基于改进YOLOv5(You Only Look Once version 5)的钢板表面缺陷检测算法。在YOLOv5的基础上将CBAM(Convolution Block Attention Module)注意力模块嵌入到主干网络中,提高网络检测精度。加入上下文增强模块,提高了算法对小目标的检测性能。使用NWD(Normalized Wasserstein Distance)度量标准代替原YOLOv5中的IoU(Intersection over Union)度量,提高了网络对裂纹缺陷的识别精确度。实验结果表明,钢板表面缺陷检测算法对裂纹、夹杂、斑块、麻点、压入氧化铁皮、划痕6类缺陷的平均检测精度达到了88.9%,每秒帧数达到110.4 frame·s-1,其中小目标裂纹准确率达到75%。
